Fear of snakes, also known as ophidiophobia, is a very common form of phobia. Depending on the source one relies upon, fear of snakes is somewhere between the first and fifth most common phobias in the general population, along with phobias like fears of spiders and heights. This phobia is a subset of herpetophobia, fear of reptiles; if someone fears reptiles in general, not just snakes, that person is technically experiencing herpetophobia, not ophidiophobia.
The reasons fear of snakes is so widespread are complicated. Research by scientists interested in psychology and evolution seems to suggest that humans are primed to be more observant around snakes, possibly because of the dangers they pose. People are more likely to notice snakes and to be aware of their movements, but they are not actually inherently afraid of them. Like other phobias, fear of snakes is learned.
People can learn to be afraid of snakes as a result of not knowing very much about snakes, reading about frightening snakes, seeing snakes used in practical jokes to scare people, and through cultural beliefs about snakes. Many societies reinforce fear of snakes with religious beliefs and superstitions, making people on edge around snakes and contributing to the development of a fear of snakes. Other cultures, however, revere snakes, and it is notable that their populations tend to demonstrate less ophidiophobia, illustrating that the fear is learned rather than innate.
For someone who has a fear of snakes, being around snakes, hearing conversations about snakes, or seeing representations of snakes in pictures and videos can be very stressful. Panic symptoms like a cold sweat, racing heart, nausea, dizziness, and confusion can develop. People may go out of their way to avoid settings where snakes may be present or where people might talk about them. Treatment of snake phobia involves slowly desensitizing people in controlled settings.
Making fun of a phobia can make it more difficult for someone to recover from it, as can trying to force people to move along in the treatment of a phobia more quickly than they are comfortable with. If someone is in treatment for fear of snakes, surprising the person with snake-related things can set back the person's therapy and potentially make the phobia worse. Friends and family can be supportive by respecting the boundaries of the person in treatment and asking if there is anything they can do to help.